Anfibatide Treatment in STEMI Patients

1. Aged 18-75 years;
2. Fulfill the standard of direct PCI: ST Segment Elevation Myocardial Infarction occurred \< 12 hours (ST Segment Elevation or New Left Bundle Branch Block (LBBB), combined myocardial ischemia chest pain medical history or the dynamic change of cardiac marker (troponin and/or CK-MB);
3. Patients who will receive PCI and suitable for angioplasty and stent placement;
4. Patients, or their family or guardian give signed informed consent forms.

Exclusion Criteria:

1. Patients with weight \< 50kg;
2. Patients with severe hepatic or renal dysfunction, alanine aminotransferase (ALT) exceeds 3 times the normal maximum reference level, creatinine clearance level \< 30ml/min or serum creatinine ≥ 200μmol/L or ≥2.5mg/dl;
3. Patients with severe hemodynamic instability;
4. Patients who will receive 2 times or more PCI treatment;
5. Patients with heart function in decompensatory phase (Killip grade 3-4) or cardiac shock;
6. Patients with untreated hypertension (SBP > 180mmHg or DBP > 110mmHg) or hypotension shock (SBP \< 90mmHg);

7. Patients received GPIIb/IIIa receptor antagonists and/or thrombolytic therapy before randomization;

   1. Used eptifibatide and tirofiban in the past 12 hours before the randomization;
   2. Used abxicimab in the past 7 days before the randomization;
   3. Have received thrombolytic therapy before the randomization;
8. Patients who need a long-term treatment of clopidogrel;
9. Patients who have received enoxaparin sodium injection before the surgery;

10. Patients who have hemorrhage risk:

    1. Suffered from ischemic stroke or transient ischemic attack (TIA) in the past 12 months;
    2. Suffered from hemorrhage stroke, or other life-long neuronal dysfunction;
    3. Suffered from tumor, arteriovenous malformation in brain and aneurysms;
    4. Suffered from traumatic brain injury in the past 3 months, or received major surgery;
    5. Received percutaneous coronary intervention (PCI) in the past 6 months;
    6. Have received coronary artery bypass graft therapy (CABG);
    7. Receiving long-term oral anticoagulants therapy;
    8. Suffered from active peptic ulcer, urinary and reproductive tract hemorrhage, or other active hemorrhage.

11. Patients with coagulation disorder:

    1. Known as international normalized ratio > 2*;
    2. Patients with coagulation abnormalities or other hemorrhagic tendency (including inherited hemorrhagic diseases, e.g. Von Willebrand disease or hemophilia; acquired hemorrhagic diseases; and other clinically identified hemorrhagic diseases with unsolved rationale);
    3. Hematology test shows platelet count \< 100x109mm3/L, or hemoglobin \< 100g/L;
    4. Recorded clopidogrel-related thrombocytopenia or agranulocytosis;
12. Life expectancy \< 1 year;
13. Patients who have implemented with pacemaker, and contraindicated to MRI examination;
14. Patients who are allergic constitution or allergic to any component of aspirin, clopidogrel, creatinine, antiplatelet thrombolysin and investigational product;
15. Women in pregnant or lactation period, or women of child-bearing age do not take efficient contraception measures;
16. Patients who are participating or will be participating in other clinical trials;
17. Patients who have participated in clinical trials of antiplatelet thrombolysin or other related trials;
18. Patients who are not suitable for participating in this clinical trial according to the investigator's judgment, including who are unable or unwilling to follow the protocol;
19. Patients who participated in other clinical trials in the past 3 months.